/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com * * This program is free software; you can redistribute it and/or * modify it under the terms of version 2 of the GNU General Public * License as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. */#include <linux/bpf.h>#include <linux/rcupdate.h>#include <linux/random.h>#include <linux/smp.h>#include <linux/ktime.h>#include <linux/sched.h>#include <linux/uidgid.h> /* If kernel subsystem is allowing eBPF programs to call this function, * inside its own verifier_ops->get_func_proto() callback it should return * bpf_map_lookup_elem_proto, so that verifier can properly check the arguments * * Different map implementations will rely on rcu in map methods * lookup/update/delete, therefore eBPF programs must run under rcu lock * if program is allowed to access maps, so check rcu_read_lock_held in * all three functions. */static u64 bpf_map_lookup_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5){	/* verifier checked that R1 contains a valid pointer to bpf_map	 * and R2 points to a program stack and map->key_size bytes were	 * initialized	 */	struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;	void *key = (void *) (unsigned long) r2;	void *value; 	WARN_ON_ONCE(!rcu_read_lock_held()); 	value = map->ops->map_lookup_elem(map, key); 	/* lookup() returns either pointer to element value or NULL	 * which is the meaning of PTR_TO_MAP_VALUE_OR_NULL type	 */	return (unsigned long) value;} const struct bpf_func_proto bpf_map_lookup_elem_proto = {	.func		= bpf_map_lookup_elem,	.gpl_only	= false,	.ret_type	= RET_PTR_TO_MAP_VALUE_OR_NULL,	.arg1_type	= ARG_CONST_MAP_PTR,	.arg2_type	= ARG_PTR_TO_MAP_KEY,}; static u64 bpf_map_update_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5){	struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;	void *key = (void *) (unsigned long) r2;	void *value = (void *) (unsigned long) r3; 	WARN_ON_ONCE(!rcu_read_lock_held()); 	return map->ops->map_update_elem(map, key, value, r4);} const struct bpf_func_proto bpf_map_update_elem_proto = {	.func		= bpf_map_update_elem,	.gpl_only	= false,	.ret_type	= RET_INTEGER,	.arg1_type	= ARG_CONST_MAP_PTR,	.arg2_type	= ARG_PTR_TO_MAP_KEY,	.arg3_type	= ARG_PTR_TO_MAP_VALUE,	.arg4_type	= ARG_ANYTHING,}; static u64 bpf_map_delete_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5){	struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;	void *key = (void *) (unsigned long) r2; 	WARN_ON_ONCE(!rcu_read_lock_held()); 	return map->ops->map_delete_elem(map, key);} const struct bpf_func_proto bpf_map_delete_elem_proto = {	.func		= bpf_map_delete_elem,	.gpl_only	= false,	.ret_type	= RET_INTEGER,	.arg1_type	= ARG_CONST_MAP_PTR,	.arg2_type	= ARG_PTR_TO_MAP_KEY,}; static u64 bpf_get_prandom_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5){	return prandom_u32();} const struct bpf_func_proto bpf_get_prandom_u32_proto = {	.func		= bpf_get_prandom_u32,	.gpl_only	= false,	.ret_type	= RET_INTEGER,}; static u64 bpf_get_smp_processor_id(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5){	return raw_smp_processor_id();} const struct bpf_func_proto bpf_get_smp_processor_id_proto = {	.func		= bpf_get_smp_processor_id,	.gpl_only	= false,	.ret_type	= RET_INTEGER,}; static u64 bpf_ktime_get_ns(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5){	/* NMI safe access to clock monotonic */	return ktime_get_mono_fast_ns();} const struct bpf_func_proto bpf_ktime_get_ns_proto = {	.func		= bpf_ktime_get_ns,	.gpl_only	= true,	.ret_type	= RET_INTEGER,}; static u64 bpf_get_current_pid_tgid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5){	struct task_struct *task = current; 	if (!task)		return -EINVAL; 	return (u64) task->tgid << 32 | task->pid;} const struct bpf_func_proto bpf_get_current_pid_tgid_proto = {	.func		= bpf_get_current_pid_tgid,	.gpl_only	= false,	.ret_type	= RET_INTEGER,}; static u64 bpf_get_current_uid_gid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5){	struct task_struct *task = current;	kuid_t uid;	kgid_t gid; 	if (!task)		return -EINVAL; 	current_uid_gid(&uid, &gid);	return (u64) from_kgid(&init_user_ns, gid) << 32 |		from_kuid(&init_user_ns, uid);} const struct bpf_func_proto bpf_get_current_uid_gid_proto = {	.func		= bpf_get_current_uid_gid,	.gpl_only	= false,	.ret_type	= RET_INTEGER,}; static u64 bpf_get_current_comm(u64 r1, u64 size, u64 r3, u64 r4, u64 r5){	struct task_struct *task = current;	char *buf = (char *) (long) r1; 	if (!task)		return -EINVAL; 	memcpy(buf, task->comm, min_t(size_t, size, sizeof(task->comm)));	return 0;} const struct bpf_func_proto bpf_get_current_comm_proto = {	.func		= bpf_get_current_comm,	.gpl_only	= false,	.ret_type	= RET_INTEGER,	.arg1_type	= ARG_PTR_TO_STACK,	.arg2_type	= ARG_CONST_STACK_SIZE,};